It appeared in An Heir to Spare, when Zenoheld got angry at Prince Hydron for not retrieving the Phantom Data, and finding out that he slipped on letting the Brawlers know about the Alternative. Zenoheld used the Agonizer to torture Hydron, thus punishing him for his actions.
- The Agonizer's role is similar to the torture droid's in Star Wars: A New Hope.
- The Agonizer looks somewhat similar to a Dalek from the Doctor Who series.
- Its name is similar to the word agonise thus its horrible role.